server/thread.c

   1 /*
   2  * Server-side thread management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <fcntl.h>
   9 #include <signal.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/types.h>
  14 #include <sys/uio.h>
  15 #include <unistd.h>
  16
  17 #include "winnt.h"
  18 #include "winerror.h"
  19 #include "server.h"
  20 #include "server/thread.h"
  21
  22
  23 /* thread queues */
  24
  25 struct wait_queue_entry
  26 {
  27     struct wait_queue_entry *next;
  28     struct wait_queue_entry *prev;
  29     struct object           *obj;
  30     struct thread           *thread;
  31 };
  32
  33 struct thread_wait
  34 {
  35     int                     count;      /* count of objects */
  36     int                     flags;
  37     struct timeval          timeout;
  38     struct wait_queue_entry queues[1];
  39 };
  40
  41 /* asynchronous procedure calls */
  42
  43 struct thread_apc
  44 {
  45     void                   *func;    /* function to call in client */
  46     void                   *param;   /* function param */
  47 };
  48 #define MAX_THREAD_APC  16  /* Max outstanding APCs for a thread */
  49
  50
  51 /* thread operations */
  52
  53 static void dump_thread( struct object *obj, int verbose );
  54 static int thread_signaled( struct object *obj, struct thread *thread );
  55 static void destroy_thread( struct object *obj );
  56
  57 static const struct object_ops thread_ops =
  58 {
  59     dump_thread,
  60     add_queue,
  61     remove_queue,
  62     thread_signaled,
  63     no_satisfied,
  64     no_read_fd,
  65     no_write_fd,
  66     no_flush,
  67     no_get_file_info,
  68     destroy_thread
  69 };
  70
  71 static struct thread *first_thread;
  72
  73
  74 /* create a new thread */
  75 struct thread *create_thread( int fd, void *pid, int *thread_handle,
  76                               int *process_handle )
  77 {
  78     struct thread *thread;
  79     struct process *process;
  80
  81     if (!(thread = mem_alloc( sizeof(*thread) ))) return NULL;
  82
  83     if (pid) process = get_process_from_id( pid );
  84     else process = create_process();
  85     if (!process)
  86     {
  87         free( thread );
  88         return NULL;
  89     }
  90
  91     init_object( &thread->obj, &thread_ops, NULL );
  92     thread->client_fd = fd;
  93     thread->process   = process;
  94     thread->unix_pid  = 0;  /* not known yet */
  95     thread->name      = NULL;
  96     thread->mutex     = NULL;
  97     thread->wait      = NULL;
  98     thread->apc       = NULL;
  99     thread->apc_count = 0;
 100     thread->error     = 0;
 101     thread->state     = STARTING;
 102     thread->exit_code = 0x103;  /* STILL_ACTIVE */
 103     thread->next      = first_thread;
 104     thread->prev      = NULL;
 105     thread->priority  = THREAD_PRIORITY_NORMAL;
 106     thread->affinity  = 1;
 107     thread->suspend   = 0;
 108
 109     if (first_thread) first_thread->prev = thread;
 110     first_thread = thread;
 111     add_process_thread( process, thread );
 112
 113     *thread_handle = *process_handle = -1;
 114     if (current)
 115     {
 116         if ((*thread_handle = alloc_handle( current->process, thread,
 117                                             THREAD_ALL_ACCESS, 0 )) == -1)
 118             goto error;
 119     }
 120     if (current && !pid)
 121     {
 122         if ((*process_handle = alloc_handle( current->process, process,
 123                                              PROCESS_ALL_ACCESS, 0 )) == -1)
 124             goto error;
 125     }
 126
 127     if (add_client( fd, thread ) == -1) goto error;
 128
 129     return thread;
 130
 131  error:
 132     if (current)
 133     {
 134         close_handle( current->process, *thread_handle );
 135         close_handle( current->process, *process_handle );
 136     }
 137     remove_process_thread( process, thread );
 138     release_object( thread );
 139     return NULL;
 140 }
 141
 142 /* destroy a thread when its refcount is 0 */
 143 static void destroy_thread( struct object *obj )
 144 {
 145     struct thread *thread = (struct thread *)obj;
 146     assert( obj->ops == &thread_ops );
 147
 148     release_object( thread->process );
 149     if (thread->next) thread->next->prev = thread->prev;
 150     if (thread->prev) thread->prev->next = thread->next;
 151     else first_thread = thread->next;
 152     if (thread->name) free( thread->name );
 153     if (thread->apc) free( thread->apc );
 154     if (debug_level) memset( thread, 0xaa, sizeof(thread) );  /* catch errors */
 155     free( thread );
 156 }
 157
 158 /* dump a thread on stdout for debugging purposes */
 159 static void dump_thread( struct object *obj, int verbose )
 160 {
 161     struct thread *thread = (struct thread *)obj;
 162     assert( obj->ops == &thread_ops );
 163
 164     fprintf( stderr, "Thread pid=%d fd=%d name='%s'\n",
 165              thread->unix_pid, thread->client_fd, thread->name );
 166 }
 167
 168 static int thread_signaled( struct object *obj, struct thread *thread )
 169 {
 170     struct thread *mythread = (struct thread *)obj;
 171     return (mythread->state == TERMINATED);
 172 }
 173
 174 /* get a thread pointer from a thread id (and increment the refcount) */
 175 struct thread *get_thread_from_id( void *id )
 176 {
 177     struct thread *t = first_thread;
 178     while (t && (t != id)) t = t->next;
 179     if (t) grab_object( t );
 180     return t;
 181 }
 182
 183 /* get a thread from a handle (and increment the refcount) */
 184 struct thread *get_thread_from_handle( int handle, unsigned int access )
 185 {
 186     return (struct thread *)get_handle_obj( current->process, handle,
 187                                             access, &thread_ops );
 188 }
 189
 190 /* get all information about a thread */
 191 void get_thread_info( struct thread *thread,
 192                       struct get_thread_info_reply *reply )
 193 {
 194     reply->pid       = thread;
 195     reply->exit_code = thread->exit_code;
 196     reply->priority  = thread->priority;
 197 }
 198
 199
 200 /* set all information about a thread */
 201 void set_thread_info( struct thread *thread,
 202                       struct set_thread_info_request *req )
 203 {
 204     if (req->mask & SET_THREAD_INFO_PRIORITY)
 205         thread->priority = req->priority;
 206     if (req->mask & SET_THREAD_INFO_AFFINITY)
 207     {
 208         if (req->affinity != 1) SET_ERROR( ERROR_INVALID_PARAMETER );
 209         else thread->affinity = req->affinity;
 210     }
 211 }
 212
 213 /* suspend a thread */
 214 int suspend_thread( struct thread *thread )
 215 {
 216     int old_count = thread->suspend;
 217     if (thread->suspend < MAXIMUM_SUSPEND_COUNT)
 218     {
 219         if (!thread->suspend++)
 220         {
 221             if (thread->unix_pid) kill( thread->unix_pid, SIGSTOP );
 222         }
 223     }
 224     return old_count;
 225 }
 226
 227 /* resume a thread */
 228 int resume_thread( struct thread *thread )
 229 {
 230     int old_count = thread->suspend;
 231     if (thread->suspend > 0)
 232     {
 233         if (!--thread->suspend)
 234         {
 235             if (thread->unix_pid) kill( thread->unix_pid, SIGCONT );
 236         }
 237     }
 238     return old_count;
 239 }
 240
 241 /* send a reply to a thread */
 242 int send_reply( struct thread *thread, int pass_fd, int n,
 243                 ... /* arg_1, len_1, ..., arg_n, len_n */ )
 244 {
 245     struct iovec vec[16];
 246     va_list args;
 247     int i;
 248
 249     assert( n < 16 );
 250     va_start( args, n );
 251     for (i = 0; i < n; i++)
 252     {
 253         vec[i].iov_base = va_arg( args, void * );
 254         vec[i].iov_len  = va_arg( args, int );
 255     }
 256     va_end( args );
 257     return send_reply_v( thread->client_fd, thread->error, pass_fd, vec, n );
 258 }
 259
 260 /* add a thread to an object wait queue; return 1 if OK, 0 on error */
 261 int add_queue( struct object *obj, struct wait_queue_entry *entry )
 262 {
 263     grab_object( obj );
 264     entry->obj    = obj;
 265     entry->prev   = obj->tail;
 266     entry->next   = NULL;
 267     if (obj->tail) obj->tail->next = entry;
 268     else obj->head = entry;
 269     obj->tail = entry;
 270     return 1;
 271 }
 272
 273 /* remove a thread from an object wait queue */
 274 void remove_queue( struct object *obj, struct wait_queue_entry *entry )
 275 {
 276     if (entry->next) entry->next->prev = entry->prev;
 277     else obj->tail = entry->prev;
 278     if (entry->prev) entry->prev->next = entry->next;
 279     else obj->head = entry->next;
 280     release_object( obj );
 281 }
 282
 283 /* finish waiting */
 284 static void end_wait( struct thread *thread )
 285 {
 286     struct thread_wait *wait = thread->wait;
 287     struct wait_queue_entry *entry;
 288     int i;
 289
 290     assert( wait );
 291     for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 292         entry->obj->ops->remove_queue( entry->obj, entry );
 293     if (wait->flags & SELECT_TIMEOUT) set_select_timeout( thread->client_fd, NULL );
 294     free( wait );
 295     thread->wait = NULL;
 296 }
 297
 298 /* build the thread wait structure */
 299 static int wait_on( struct thread *thread, int count,
 300                     int *handles, int flags, int timeout )
 301 {
 302     struct thread_wait *wait;
 303     struct wait_queue_entry *entry;
 304     struct object *obj;
 305     int i;
 306
 307     if ((count < 0) || (count > MAXIMUM_WAIT_OBJECTS))
 308     {
 309         SET_ERROR( ERROR_INVALID_PARAMETER );
 310         return 0;
 311     }
 312     if (!(wait = mem_alloc( sizeof(*wait) + (count-1) * sizeof(*entry) ))) return 0;
 313     thread->wait  = wait;
 314     wait->count   = count;
 315     wait->flags   = flags;
 316     if (flags & SELECT_TIMEOUT)
 317     {
 318         gettimeofday( &wait->timeout, 0 );
 319         if (timeout)
 320         {
 321             wait->timeout.tv_usec += (timeout % 1000) * 1000;
 322             if (wait->timeout.tv_usec >= 1000000)
 323             {
 324                 wait->timeout.tv_usec -= 1000000;
 325                 wait->timeout.tv_sec++;
 326             }
 327             wait->timeout.tv_sec += timeout / 1000;
 328         }
 329     }
 330
 331     for (i = 0, entry = wait->queues; i < count; i++, entry++)
 332     {
 333         if (!(obj = get_handle_obj( thread->process, handles[i],
 334                                     SYNCHRONIZE, NULL )))
 335         {
 336             wait->count = i - 1;
 337             end_wait( thread );
 338             return 0;
 339         }
 340         entry->thread = thread;
 341         if (!obj->ops->add_queue( obj, entry ))
 342         {
 343             wait->count = i - 1;
 344             end_wait( thread );
 345             return 0;
 346         }
 347         release_object( obj );
 348     }
 349     return 1;
 350 }
 351
 352 /* check if the thread waiting condition is satisfied */
 353 static int check_wait( struct thread *thread, int *signaled )
 354 {
 355     int i;
 356     struct thread_wait *wait = thread->wait;
 357     struct wait_queue_entry *entry = wait->queues;
 358
 359     assert( wait );
 360     if (wait->flags & SELECT_ALL)
 361     {
 362         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 363             if (!entry->obj->ops->signaled( entry->obj, thread )) goto other_checks;
 364         /* Wait satisfied: tell it to all objects */
 365         *signaled = 0;
 366         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 367             if (entry->obj->ops->satisfied( entry->obj, thread ))
 368                 *signaled = STATUS_ABANDONED_WAIT_0;
 369         return 1;
 370     }
 371     else
 372     {
 373         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 374         {
 375             if (!entry->obj->ops->signaled( entry->obj, thread )) continue;
 376             /* Wait satisfied: tell it to the object */
 377             *signaled = i;
 378             if (entry->obj->ops->satisfied( entry->obj, thread ))
 379                 *signaled += STATUS_ABANDONED_WAIT_0;
 380             return 1;
 381         }
 382     }
 383
 384  other_checks:
 385     if ((wait->flags & SELECT_ALERTABLE) && thread->apc)
 386     {
 387         *signaled = STATUS_USER_APC;
 388         return 1;
 389     }
 390     if (wait->flags & SELECT_TIMEOUT)
 391     {
 392         struct timeval now;
 393         gettimeofday( &now, NULL );
 394         if ((now.tv_sec > wait->timeout.tv_sec) ||
 395             ((now.tv_sec == wait->timeout.tv_sec) &&
 396              (now.tv_usec >= wait->timeout.tv_usec)))
 397         {
 398             *signaled = STATUS_TIMEOUT;
 399             return 1;
 400         }
 401     }
 402     return 0;
 403 }
 404
 405 /* send the select reply to wake up the client */
 406 static void send_select_reply( struct thread *thread, int signaled )
 407 {
 408     struct select_reply reply;
 409     reply.signaled = signaled;
 410     if ((signaled == STATUS_USER_APC) && thread->apc)
 411     {
 412         struct thread_apc *apc = thread->apc;
 413         int len = thread->apc_count * sizeof(*apc);
 414         thread->apc = NULL;
 415         thread->apc_count = 0;
 416         send_reply( thread, -1, 2, &reply, sizeof(reply),
 417                     apc, len );
 418         free( apc );
 419     }
 420     else send_reply( thread, -1, 1, &reply, sizeof(reply) );
 421 }
 422
 423 /* attempt to wake up a thread */
 424 /* return 1 if OK, 0 if the wait condition is still not satisfied */
 425 static int wake_thread( struct thread *thread )
 426 {
 427     int signaled;
 428
 429     if (!check_wait( thread, &signaled )) return 0;
 430     end_wait( thread );
 431     send_select_reply( thread, signaled );
 432     return 1;
 433 }
 434
 435 /* sleep on a list of objects */
 436 void sleep_on( struct thread *thread, int count, int *handles, int flags, int timeout )
 437 {
 438     assert( !thread->wait );
 439     if (!wait_on( thread, count, handles, flags, timeout ))
 440     {
 441         /* return an error */
 442         send_select_reply( thread, -1 );
 443         return;
 444     }
 445     if (!wake_thread( thread ))
 446     {
 447         /* we need to wait */
 448         if (flags & SELECT_TIMEOUT)
 449             set_select_timeout( thread->client_fd, &thread->wait->timeout );
 450     }
 451 }
 452
 453 /* timeout for the current thread */
 454 void thread_timeout(void)
 455 {
 456     assert( current->wait );
 457     end_wait( current );
 458     send_select_reply( current, STATUS_TIMEOUT );
 459 }
 460
 461 /* attempt to wake threads sleeping on the object wait queue */
 462 void wake_up( struct object *obj, int max )
 463 {
 464     struct wait_queue_entry *entry = obj->head;
 465
 466     while (entry)
 467     {
 468         struct wait_queue_entry *next = entry->next;
 469         if (wake_thread( entry->thread ))
 470         {
 471             if (max && !--max) break;
 472         }
 473         entry = next;
 474     }
 475 }
 476
 477 /* queue an async procedure call */
 478 int thread_queue_apc( struct thread *thread, void *func, void *param )
 479 {
 480     struct thread_apc *apc;
 481     if (!func)
 482     {
 483         SET_ERROR( ERROR_INVALID_PARAMETER );
 484         return 0;
 485     }
 486     if (!thread->apc)
 487     {
 488         if (!(thread->apc = mem_alloc( MAX_THREAD_APC * sizeof(*apc) )))
 489             return 0;
 490         thread->apc_count = 0;
 491     }
 492     else if (thread->apc_count >= MAX_THREAD_APC) return 0;
 493     thread->apc[thread->apc_count].func  = func;
 494     thread->apc[thread->apc_count].param = param;
 495     thread->apc_count++;
 496     wake_thread( thread );
 497     return 1;
 498 }
 499
 500 /* kill a thread on the spot */
 501 void kill_thread( struct thread *thread, int exit_code )
 502 {
 503     if (thread->state == TERMINATED) return;  /* already killed */
 504     if (thread->unix_pid) kill( thread->unix_pid, SIGTERM );
 505     remove_client( thread->client_fd, exit_code ); /* this will call thread_killed */
 506 }
 507
 508 /* a thread has been killed */
 509 void thread_killed( struct thread *thread, int exit_code )
 510 {
 511     thread->state = TERMINATED;
 512     thread->exit_code = exit_code;
 513     if (thread->wait) end_wait( thread );
 514     abandon_mutexes( thread );
 515     remove_process_thread( thread->process, thread );
 516     wake_up( &thread->obj, 0 );
 517     release_object( thread );
 518 }